Speaker: James Nightingale (Durham)

Date: Thursday 16 November 2023

Time: 14:00

Location: Biomedical Building C44

Galaxies, Dark Matter and Supermassive Black Holes with Strong Gravitational Lensing

In a strong gravitational lens, a background source galaxy appears multiple times, because its light is deflected by an intervening foreground galaxy’s mass. Lens modeling reverses the source galaxy’s deflected emission and reconstructs the foreground lens’s projected gravitational potential at an unprecedented level of detail, providing astronomers with a powerful tool to study the Universe. I discuss how lensing can further traditional studies of galaxy structure, offering new insights on complex features in their mass distributions, such as boxiness/diskiness, asymmetric twists and stellar/dark matter offsets. I show how invisible dark matter substructures near the lensed source galaxy are observed as "perturbations" to its lensed emission, which can constrain dark matter models. I present the first measurement of a supermassive black hole mass via strong lensing, the detection of a M_Bh = 3.27 ± 2.12 x 10¹⁰M_Sun supermassive black hole (SMBH) in the z = 0.451 strong lens Abell 1201. Finally, with Euclid (launched July 2023) poised to find ~100,000 strong lenses, I look ahead to the scientific opportunities awaiting strong lensing.